Experience the next level of connectivity with THVD1426 and STM32F446RE
Data harmony in every byte: Unleash the potential of full-duplex RS485
Published Oct 08, 2024
Click board™
RS485 8 Click
Dev Board
Nucleo 64 with STM32F446RE MCU
Compiler
NECTO Studio
MCU
STM32F446RE
Empower your network with our full-duplex RS485 transceiver, offering a robust solution for real-time, high-speed, and bidirectional data exchange, setting a new standard for communication reliability.
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Hardware Overview
How does it work?
RS485 8 Click is based on the THVD1426, an RS485 transceiver with auto-direction control and ESD protection from Texas Instruments. The THVD1426 has one termination resistor over the A/B that can be enabled over the TERM jumper. The RS485 8 Click comes with the SM712, a 600W asymmetrical TVS diode array from Littelfuse, along with the termination resistor. This diode array is designed to protect the RS485 applications with asymmetrical working voltages from -7V up to 12V, thus making it safe from damage due to
electrostatic discharge, fast electrical transients, and lightning-induced surges. Both the diode array and the termination resistor are placed near the RS485 screw terminal, with which you can connect the RS485 8 Click to your application's other end. RS485 8 Click uses the UART interface to communicate with the host MCU with commonly used UART RX and TX pins. The auto-direction mode on the RS485 8 Click is set by default and disabled with a pull-down resistor. It can be enabled with the logic HIGH state on the
EN pin of the mikroBUS™ socket. You can control the driver and receiver using the data input pin RX by enabling the transceiver. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.
Features overview
Development board
Nucleo-64 with STM32F446RE MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin
headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is
provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M4
MCU Memory (KB)
512
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
131072
You complete me!
Accessories
Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Nucleo 64 with STM32F446RE MCU as your development board.
Track your results in real time
Application Output
This Click board can be interfaced and monitored in two ways:
Application Output- Use the "Application Output" window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.
UART Terminal- Monitor data via the UART Terminal using a USB to UART converter. For detailed instructions, check out this tutorial.
Software Support
Library Description
This library contains API for RS485 8 Click driver.
Key functions:
rs4858_generic_write- RS485 8 data writing function.rs4858_generic_read- RS485 8 data reading function.rs4858_enable_device- RS485 8 enable the device function.
Open Source
Code example
The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.
/*!
* @file main.c
* @brief RS485 8 Click Example.
*
* # Description
* This example reads and processes data from RS485 8 clicks.
* The library also includes a function for enabling/disabling
* the receiver or driver and data writing or reading.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and performs the click default configuration.
*
* ## Application Task
* This example demonstrates the use of the RS485 8 Click board.
* The app sends a "MikroE" message, reads the received data and parses it.
* Results are being sent to the UART Terminal, where you can track their changes.
*
* ## Additional Function
* - static err_t rs4858_process ( void )
*
* @author Stefan Ilic
*
*/
#include "board.h"
#include "log.h"
#include "rs4858.h"
#define PROCESS_BUFFER_SIZE 200
// Comment out the line below in order to switch the application mode to receiver.
#define DEMO_APP_TRANSMITTER
static rs4858_t rs4858;
static log_t logger;
uint8_t data_buf[ 8 ] = { 'M', 'i', 'k', 'r', 'o', 'E', '\r', '\n' };
static uint8_t app_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
static int32_t app_buf_len = 0;
/**
* @brief RS485 8 data reading function.
* @details This function reads data from device and concatenates data to application buffer.
* @param[in] ctx : Click context object.
* See #rs4858_t object definition for detailed explanation.
* @return @li @c 0 - Read some data.
* @li @c -1 - Nothing is read.
* See #err_t definition for detailed explanation.
* @note None.
*/
static err_t rs4858_process ( void );
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
rs4858_cfg_t rs4858_cfg; /**< Click config object. */
/**
* Logger initialization.
* Default baud rate: 115200
* Default log level: LOG_LEVEL_DEBUG
* @note If USB_UART_RX and USB_UART_TX
* are defined as HAL_PIN_NC, you will
* need to define them manually for log to work.
* See @b LOG_MAP_USB_UART macro definition for detailed explanation.
*/
LOG_MAP_USB_UART( log_cfg );
log_init( &logger, &log_cfg );
log_info( &logger, " Application Init " );
// Click initialization.
rs4858_cfg_setup( &rs4858_cfg );
RS4858_MAP_MIKROBUS( rs4858_cfg, MIKROBUS_2 );
if ( UART_ERROR == rs4858_init( &rs4858, &rs4858_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
rs4858_default_cfg ( &rs4858 );
#ifdef DEMO_APP_TRANSMITTER
log_info( &logger, "---- Transmitter mode ----" );
#else
log_info( &logger, "---- Receiver mode ----" );
#endif
log_info( &logger, " Application Task " );
Delay_ms( 100 );
}
void application_task ( void )
{
#ifdef DEMO_APP_TRANSMITTER
rs4858_generic_write( &rs4858, data_buf, strlen( data_buf ) );
log_info( &logger, "---- Data sent ----" );
Delay_ms( 2000 );
#else
rs4858_process( );
#endif
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
static err_t rs4858_process ( void )
{
int32_t rx_size;
char rx_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
rx_size = rs4858_generic_read( &rs4858, rx_buf, PROCESS_BUFFER_SIZE );
if ( rx_size > 0 )
{
log_printf( &logger, "%s", rx_buf );
return RS4858_OK;
}
return RS4858_ERROR;
}
// ------------------------------------------------------------------------ END
